docs: def setnodeval(delta, graph, node, key, value):
      """Change a delta to say that a node stat was set to a certain value"""
      if (
          graph in delta and 'nodes' in delta[graph] and
          node in delta[graph]['nodes'] and not delta[graph]['nodes'][node]
      ):
          return
      delta.setdefault(graph, {}).setdefault('node_val', {}).setdefault(node, {})[key] = value